Briefly, the rationale for the Conference is as follows: The stratum corneum (SC) is the primary barrier between the internal milieu of the body and the outside environment. The significance of this membrane (aa) as a barrier to environmental and occupational chemicals (including gases), (b) in retaining body water and solutes, and (c) for local and systemic drug delivery, is such that the SC is now the focus of research in a wide variety of disciplines. Because of the breadth of the research in progress, there exists no single forum at which the major inv estigators can assemble for discussion and dissemination of ideas. We believe that a Gordon Conference is therefore both timely and appropriate for this rapidly developing field.